
I got this picture off a projectionist's forum. This isn't at Western Film, it's a print of Angels and Demons somewhere in Australia. That's the film all over the floor, where it's not supposed to be.
The piece of equipment in the middle is called a platter. It consists of three revolving discs about 4 ft wide. On the bottom one you'll see a film as it's supposed to look, nicely wound in a big spool with the beginning of the film in the center and the end on the outside.
When a film plays off a platter it pays out from the center, goes over some rollers, through the projector and back onto one of the other discs. It wraps around a ring placed in the center and ends up looking the same as it started, just on a different disc.
What happened here is somehow the film was not going back onto the platter but was just spilling onto the floor. There's several things that can cause this, mostly projectionist error but sometimes it can be a equipment problem. Even something like a momentary power drop out can cause this. That's why you'll always see the projectionist at Western Film go into the booth after the power blinks, even if the film seems to be running normally.
The scary thing is the average film is 12,000 ft long, that's a lot of film to try to wrap back up manually.